Measured my tire wear (20,000+ miles at elevated pressure - 44 PSI)

[strangewierding]

The benefits of increasing the pressure in your tires is to minimize sidewall deflection when cornering and to minimize tread contact and therefore energy losses due to friction.

As dcb said the tire will not inflated beyond the diameter of the belts. The steel belts across the tread of the tire are meant to create a minimally flexible flat surface which the tread itself rides against. For that reason the tread area or crown of the tire is made of four or more plies (layers) of steel chords. The sidewall is predominantly nylon chords which allow it to flex under load. It is this combination of stiff surface and flexible sidewall which allows modern radial tires to get the longevity and performance which they do.

Increasing the air pressure (beyond MAX inflation listed on tire) to attempt to even out the wear in this situation will likely lead to a belt separation AKA a garbage tire.

I drive a '03 VW Golf TDI with 225/45R17 Toyo Versado LX on it. I run my pressure at approximately 40 PSI as I prefer the firmer ride, better handling and better economy. In the three years that I have had these tire all that I check for wear is overall evenness. You can't get better wear than that.

In summary, over-inflating your tires will even out wear to a point, but beyond that the benefits are negligible.

[KGM]

I drive on European roads (more corners) on 195/65R15 tires with 2.8bar = 40PSI
/manufacturer's recommendation - 2.3bar/

I read in extreme economy mods' test in a car magazine (Autobild) that for fuel economy it is advisable to over-inflate max +0.5bar than manufacturer's recommendation -
so as not to lose from ride comfort and safety
and that max sidewall inflation or more will lead to a faster tyre sidewalls' wear - as said before me!

But strangewierding - my 17" set (exactly the same size - 225/45R17):
the tyre workshop advised me to inflate them directly to 2.8bar (40PSI) -
as a lower profile tyre needs a higher pressure to compensate ...

In my opinion on this size 40PSI is not over-inflation - but normal

[evilskillit]

It may depend on your tire. I have some 215/40/17 sport tires on my car rated at max 50psi. Running at just a couple of PSI below max they went bald in the middle first and after lowering the PSI down to around 40 I notice they have a slightly cupped shape now, like the diagrams at NTB show.

If I'd been driving harder, more often like most sport tire owners I might have worn down more of the edge and have more even wear. All things considered I probably increased the life of the tire because now at 40 it's going to wear on the edges faster than in the middle. Is this good for the tire, or safe? Not qualified to say. Have I saved anything on gas, maybe? Does the car feel like it rolls a lot better at 40psi and up? Definitely. Just my 2 cents.

[strangewierding]

What I meant by what I said is that you stay within the maximum pressure capacity of your tire. Lower profile tires tend to have a higher max pressure (44psi as opposed to 35psi). As such 40 psi would not be over-inflating for the 225's, but would be for the 195's. (Though in reality due to safety factors the tire COULD potentially run between 20-50% more air than what is listed; I do not recommend this)

[F8L]

Thank you for the data.

I performed a similar test with Goodyear Integritys (185/65/15) on my old Prius and tire wear was very even at up to 60psi.

Because mpg doesn't significantly increase with pressures higher than sidewall max I tend to stay around the 40-44psi range nowadays.

[MaxHedrm]

Originally Posted by KGM

But strangewierding - my 17" set (exactly the same size - 225/45R17):
the tyre workshop advised me to inflate them directly to 2.8bar (40PSI) -
as a lower profile tyre needs a higher pressure to compensate ...

That's because it is the air that holds up the car, not the tire. So, the lower the profile, the less volume you have. The less volume the more pressure for the same amount of air. Heavy truck tires inflate even higher.

[Russjd]

This over-inflation is a VERY BAD IDEA and not worth the mileage savings.
These hi pressures causes less contact area on the road.
What about a panic stop?
What about a panic stop IN THE RAIN.
The damages to single / multiple cars involved is not worth it.
The life you end maybe... mine, someone you know, an innocent person or your own.

[WE0H]

Under inflation is a very bad idea. I run my tires at the max rated pressure molded into the sidewalls. Never had a tire failure, never had an accident, my car's handle way better than running them at Mr Donut pressures.

Mike

[F8L]

Originally Posted by Russjd

This over-inflation is a VERY BAD IDEA and not worth the mileage savings.
These hi pressures causes less contact area on the road.
What about a panic stop?
What about a panic stop IN THE RAIN.
The damages to single / multiple cars involved is not worth it.
The life you end maybe... mine, someone you know, an innocent person or your own.

If you are going to make blanket statements such as the FUD above you should provide us with details and data that proves your point.

[Russjd]

Blanket Statement?
FUD?

Because you Never had a tire failure,
Because you Never had an accident,
what instrumentation are you using to determine "your car's handle way better"?

I go buy.... max tire contact = max braking, cornering (at "normal" speeds)